It’s accurate for storing financial (and other) values that need precision but don’t exceed four decimal places. You can show just the date, just the time, or a combination of both-all in various display formats.Ĭurrency is a fixed-point number with four decimal places. Date/Time is a special data type since many pieces of information are reported in the one value. The decimal portion indicates the fraction of a day, where midnight is 0 and noon is 0.5. The “whole” part of the number measures the days that have passed since December 30, 1899. By default, autonumber values start at 1 and increase in increments of 1.ĭate/Time is stored as a number. Generally, it’s best to stick to simple data types.įor Number, the critical distinction is made in the Field Size property: Byte, Integer, Long Integer, Single, Double, Replication ID, and Decimal.ĪutoNumber is a special form of Long Integer that’s generally used for primary keys because it automatically gets a value when a new record is created. Because Long Text is stored differently, it can create issues, so use it sparingly, if at all-a better strategy is to store external files externally. For example, if you have a code that’s only seven characters, limiting the field size to 7 results in better performance and helps reduce errors, such as someone entering an invalid eight-character code.īy contrast, Long Text (formerly Memo) is a complex data type because it’s stored in “pages”-and you wouldn’t want to use an entire piece of paper for writing just one line! A Long Text field can store up to 65,536 characters if the data is entered into Access directly.
It’s a good idea to consider the actual length of the data that will be used in that field and set the field size accordingly. A field with this data type is limited to a maximum of 255 characters in length, which is controlled by field size. Short Text (formerly Text) is a simple data type. Figure 2 shows data types used in our sample database. Which of those it will be is determined by the Field Size property. For example, a field with the Data Type property set to Number could be a long integer, decimal, or some other type of number. It can be helpful to think of them as general categories of data, with the Field Size property providing more specifics about the “true” data type. Some of the data types are simple and straightforward while others are complex. Figure 1 shows the Data Type dropdown menu for when you define fields in an Access table.
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